Check the manifest before someone tries to install the app.

What does the web app manifest and icon validator do?

Paste or upload a web app manifest to validate its JSON, core identity fields, start URL, display mode, icon sizes, MIME types, and maskable declarations. The immediate result is a manifest and PWA icon validation report. That makes the tool useful when a focused question needs an answer before a file is handed off, a campaign is trafficked, or a production workflow begins.

The scope is intentionally narrow. It is designed for checking one favicon, manifest, or small-size legibility decision, not for replacing the complete production process. A useful result should make the next decision clearer while leaving the original file, design, or workflow under the user’s control.

Your files and inputs are processed locally in this browser and are not uploaded to Hypermatic. Local processing reduces unnecessary data exposure, but it does not remove the need to follow the privacy, confidentiality, and retention requirements that apply to the source material.

How should the web app manifest and icon validator be used?

Start with the same input that will be used in production whenever possible. Draft content, substitute files, and approximate dimensions can be useful during exploration, but the final check should use the actual export, final copy, destination, or supported range.

Work through the steps in order and keep the generated result beside the source. If the result identifies a warning, decide whether it is a real production problem, an acceptable tradeoff, or a limitation of a browser-based inspection before changing the underlying work.

• Paste the manifest JSON or choose a local .webmanifest file.
• Validate the core application fields and inventory every icon declaration.
• Add missing sizes or maskable artwork, deploy the referenced files, and verify install behavior in a supporting browser.

How should the result be interpreted?

A browser tool can make measurable signals visible, but it cannot reproduce every application, platform, rendering engine, policy, or team constraint. Treat the report as evidence for a decision rather than a universal guarantee. The strongest verification is the deployed website, resolved asset URLs, browser caches, and real install or bookmark surfaces.

Pay particular attention to edge cases that are easy to miss during a quick check: unusual fonts, long or localized content, hidden metadata, external dependencies, different aspect ratios, browser-specific behavior, and last-minute source changes. Re-run the tool whenever the production input changes materially.

• A manifest can be valid JSON while still referencing missing icon files.
• Use artwork specifically designed for a maskable safe zone.
• Test the deployed manifest over HTTPS and confirm that icon URLs resolve with the correct MIME type.

Common questions about web app manifest and icon validator

Which PWA icon sizes should a manifest include? 192 × 192 and 512 × 512 are common baseline expectations. The complete set depends on the platforms and install surfaces the application supports.

Does a valid manifest guarantee that a site is installable? No. Installability also depends on HTTPS, browser support, service-worker or platform requirements, resolved assets, engagement behavior, and current browser policy.

Is the web app manifest and icon validator free? Yes. You can use it without an account or signup. The focused result is generated directly in your browser.

When does Favvy become the better workflow?

The free tool is the right choice for a quick individual check, calculation, preview, or template. It remains useful even if the task only occurs once and no broader production workflow is needed.

Favvy becomes more practical when the same job turns into generating complete favicon, Apple touch icon, PWA, HTML, and manifest asset sets from Figma. At that point, keeping the work close to the Figma source reduces repeated exports, copy-and-paste steps, inconsistent decisions, and handoff drift.

Before adopting any workflow, compare the time spent on the recurring manual process with the setup and review required by the tool. The goal is not to add another application; it is to remove repetitive work while preserving the quality checks that still need human judgment.